Anthropic Says It’s Taking Claude Fable 5 Offline to Comply With US Government Order

Anthropic says it’s disabling two AI models it launched earlier this week, Claude Fable 5 and Mythos 5, to comply with an export control directive it received Friday afternoon from the US government citing national security concerns.

The unprecedented incident marks the latest flashpoint between Anthropic and the Trump administration. While the company says the order asked it to suspend access to “any foreign national, whether inside or outside the United States, including foreign national Anthropic employees,” it has removed access for all of its customers to ensure compliance.

Earlier this year, Trump’s Department of Defense labeled Anthropic a “supply chain risk” after the Claude-maker sought to draw red lines over how the US military could use its technology. The designation effectively barred government agencies and contractors from using Anthropic’s technology. Anthropic responded by filing lawsuits against the Trump administration.

On Tuesday, Anthropic publicly released Claude Fable 5, a version of the company’s Mythos AI model with safeguards that prevent it from answering questions about cybersecurity, biology, and chemistry. Prior to the public release, which Anthropic said it had conducted in collaboration with the US government, the Mythos Preview AI model had a limited rollout in April. The goal was to give companies and organizations an opportunity to use its powerful cybersecurity capabilities to improve their defenses, and stem concerns that the technology could be exploited by bad actors to develop powerful hacking tools.

In a blog post on Friday, Anthropic says it received a letter from the US government at 5:21 pm ET. “The letter did not provide specific details of its national security concern,” Anthropic wrote.

“Our understanding is that the government believes it has become aware of a method of bypassing, or ‘jailbreaking’ Fable 5,” the company added. “We reviewed a demonstration of this specific technique being used to identify a small number of previously known, minor vulnerabilities. These vulnerabilities all appear relatively simple, and we have found that other publicly-available models are able to discover them as well without requiring a bypass.”

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In the blog post, the company argued that it has implemented strong safeguards to reduce the likelihood of Claude Fable 5’s misuse. Anthropic also claimed that the jailbreak the US government found for Claude Fable 5 was narrow, and would not have made an attacker meaningfully more dangerous than they would have been with another AI model.

“To date, the government has only given us verbal evidence of a potential narrow, non-universal jailbreak, which essentially consists of asking the model to read a specific codebase and fix any software flaws,” the company said in its blog post. “Our understanding is that one potential jailbreak was shared with the government.”

Spokespeople for the White House and US Commerce Department did not immediately respond to WIRED’s request for comment.

Anthropic CEO Dario Amodei said in a policy essay earlier this week that he and the company support a fair, structured, and transparent government process that would block the release of unsafe AI models. In the company’s blog post on Friday, Anthropic argued that “this action does not adhere to those principles.”